The day polio met its match: Celebrating 70 years of the Salk vaccine

April 11, 2025

The day polio met its match: Celebrating 70 years of the Salk vaccine

April 11, 2025

Seventy years ago, on April 12, 1955, a scientific breakthrough changed the course of public health and inspired hope worldwide. The polio vaccine developed by Jonas Salk and colleagues was officially declared “safe, effective, and potent”—a moment heralded as a triumph of medicine over one of the most feared diseases of the 20th century.

“The most successful public health interventions are often overlooked or underappreciated—we take them for granted because you don’t see what’s not there,” says Salk Institute President Gerald Joyce. “The near-total absence of polio in the US over the past several decades makes it difficult for most of us to understand just how terrible it was and too easy to devalue the heroic efforts that went into eradicating it.

“On this anniversary, join us in remembering what polio took away from many families and communities, the hope and security that Jonas Salk brought us, and the value of vaccines to the past, present, and future of humanity.”

On this milestone anniversary, here are some key things to know:

Polio was terrifying.

In the early 20th century, poliomyelitis, or polio, struck fear into families around the globe. The victims of the disease, primarily children, could face paralysis, lifelong disabilities, or even death. Several polio epidemics occurred between 1948 and 1955 in the US. The outbreak of 1952 was particularly devastating, claiming more than 3,000 lives and leaving tens of thousands with severe impairments. The sight of children in wheelchairs and iron lungs (large machines that helped them breathe) and of parents keeping their children away from public spaces like swimming pools and fairs underscored the desperation for a cure.

Jonas Salk continues to be a hero to many.

Jonas Salk, a young virologist and researcher, took on the challenge of defeating polio. Unlike other vaccine developers of the time, who experimented with live or weakened viruses, Salk pursued a vaccine based on killed poliovirus. This innovative approach—safer and simpler to produce—became the cornerstone of his work.

By 1954, Salk’s vaccine underwent rigorous testing in one of the largest clinical trials in history. Nearly 2 million children, affectionately called the “Polio Pioneers,” participated. When the announcement came in Ann Arbor, Michigan on April 12, 1955, that the vaccine was both safe and effective, celebrations erupted across the nation. It was a day many compared to V-E Day or V-J Day, signaling victory in a battle against a relentless enemy.

Jonas Salk’s decision not to patent the vaccine—famously stating, “Could you patent the sun?”—ensured its widespread distribution. This act of altruism exemplified his commitment to humanity. In 1960, Salk furthered his vision of advancing science for public good by founding the Salk Institute for Biological Studies. Designed in collaboration with renowned architect Louis Kahn, the Institute continues to be a hub for life-changing research.

The polio vaccine’s impact still resonates today.

The introduction of Salk’s vaccine led to an unprecedented drop in polio cases. In the US, the average annual number of cases plummeted from 45,000 before the vaccine to just 910 by 1962. Worldwide, polio cases have fallen by more than 99 percent since the vaccine’s introduction, thanks to expanded immunization programs and collaborative global efforts. Today, polio is on the verge of eradication, a testament to the power of vaccines and public health initiatives.

The work of safeguarding humanity is never truly done.

Seventy years later, the success of the Salk vaccine serves as a powerful reminder of what science and collaboration can achieve. It also underscores the importance of global vaccination efforts in preventing disease and protecting public health. While polio has been nearly eradicated, the continued fight to eliminate the disease entirely reminds us that the work of safeguarding humanity is never truly done.

As we celebrate this landmark anniversary, let us honor Jonas Salk and all those who contributed to this extraordinary achievement. Their efforts not only conquered polio but also paved the way for future scientific innovations—at the Salk Institute and elsewhere—that save lives and bring hope to millions worldwide.